Airplane fuel tank safety device



Nov. 10, 1942. v VANIDAAM 2,301,483

AIRPLANE FUEL TANK SAFETY DEVICE Filed Nov. 3, 1939 2 Sheets-Sheet lPatented Nov. 10, 1942 UNITED STATES PATENT OFFICE AIRPLANE FUEL TANKSAFETY DEVICE Gerr it Van Daam. Bufl'alo, N. Y. Application November 3,1939, Serial No. 302,707 3 Claims. (01. 220-83) This invention relatesgenerally to safety devices for fuel tanks of airplanes and moreparticularly means for preventing the leakage and explosion of saidtanks under all conditions.

According to the teachings of the prior art with which I am familiar, notanks for fuel have been provided to prevent leakage therefrom upon anobject such as a bullet passing through the walls of the tank. All ofthe tanks now installed in airplanes tend to explode when there is a badwreck, because of the impact causing high pressure and heat in the tank.

It is accordingly an object of my invention to remedy the above andother defects in fuel tanks used in airplane construction and it is moreparticularly an object of my invention to provide means for ejecting anextinguishing fluid over the surface of the fuel in the fuel tank toprevent burning or explosion thereof upon the happening of certainevents.

Another object of my invention is to provide a tank which will withstandpuncture by a comparatively large object, such as a bullet, withoutleakage of the tank.

Another object of my invention is to provide means on the externalsurface of an airplane which will release an extinguishing fluid in afuel tank, upon wreckage of the airplane.

Another object of my invention is to provide means for cutting off thefuel to the carbureter of the motor of the plane as well as ejectingextinguishing fluid over the surface of the fuel ,in the fuel tank of anairplane.

Another object of my invention is to provide manual means whereby theoperator of the plane may cut off the fuel to the carbureter and releasean extinguishing fluid in the fuel tank of the airplane. V

Another object of my invention is to provide means to reduce the firehazard in an airplane to an absolute minimum.

Other objects ofmy invention will become evident in the followingdetailed description taken in conjunction with the accompanying drawingsin which, a

Fig. l is a perspective view of an airplane showing my release triggersdisposed on the bottom of the wings of an airplane.

Fig. 2 is a side elevational view of an airplane with parts broken awayto show the .disposition of my invention in an airplane.

Fig. 3 is a top plan view of a wing of an'airplane with the top partremoved to show the releasing wires assembled therein.

with parts broken away showing my novel trigger and releasing wires.

Fig. 5 is an enlarged perspective view of means disposed in the wings ofan airplane for connecting the release wires.

Fig. 6 is an enlarged diagrammatic view with parts broken away of mynovel fuel. tank for an airplane with attachments for cutting off thefuel passing therefrom and also for providing extinguishing fluidthrough the top of the tank.

Fig. 7 is a top plan fragmentary view of the gear valve in the fuel lineleading to the carbureter.

Fig. 8 is a diagrammatic view showing a modified form of constructionfor releasing extinguishing fluid in the fuel tank and for cutting offthe fuel to the carburetor.

Referring to the drawings, Fig. 6 discloses a fuel tank I for use inairplanes having an inner lining 2 and an outer lining 3. Disposedbetween the inner and outer linings 2 and 3 is a compressed rubber 4 orany other similar elastic substance. The rubber is preferably vulcanizedtogether and it is preferably rubber with bulges, bubbles orcorrugations. Pressure is applied to the rubber or other similar elasticsubstance by means of telescopically disposed and covers 5 and 6, thepressure being applied through straps I with threaded portions 8 whichpass through an aperture in flanges 9 disposed on the outer lining 3 ofthe tank I. The threaded nuts 8-a engage the threaded portion '8 of thestraps to draw the end covers inwardly towards the center of the tank Iand apply pressure to the rubber 4. It will be evident that any meansmay be used which will apply pressure to the compressed rubber l, andonly one means is here shown to apply pressure. In the means shown inFig. 6 for applying pressure to the rubber 4 in the tank I, the pressureis first applied by encircling the inner lining 2 with an outer lining 3of a strong light alloy. The straps l0 encircle the outer lining 3,which when screwed together through means of the threaded portion H andnut l2 cause the necessary pressure to be applied. This pressure,however, causes the material to overflow at the two ends of. the tank sothe two end covers 5 and 6 are disposed on the ends of the fuel tank andpulled together by means of the straps Fig. 4 is a side elevation of anairplane wing Plane i Wr ke I h ve provided a container l3.

wherein any form of extinguishing fluid may be contained. A piston I4 onrod I5 is urged upwardly in the container by a coil spring I6 disposedaround the rod I5 between the under side of the piston I4'and the bottomportion ll of the container I3. The container I3 is connected to the topof the fuel tank I by a pipe line I8. A nozzle I9 of any suitable typemay be disposed in the tank I to disperse the extinguishing fluid overthe whole surface of the fuel in the tank I. The rod I5 is movably butfixedly attached to the pivoted arm 2|], which is held by latchingmember 2| in a position to hold the coil spring I6 in a compressedcondition and therefore the piston I4 in the bottom of the container I3.A spring 22 on the arm 26 urges the latching portion 23 into engagementwith the latching portion 24 on the latching member 2| A handle 25 onthe arm 20 provides for the upward movement of the piston I6 manually.Any suitable means may be provided to move the latching portion 23 awayfrom the latching portion 24 on latching member 2| manually. Thelatching portion 24 of the latching member 2| is released automaticallyfrom the latching portion 23 on the arm 20 when the releasing triggers26 strike an obstruction, wherein the releasing wires 21 attached to thelatching member 2|, through pulleys 28 cause the release of the latchingmember 2| and permit the piston I4 to move upwardly through the force ofthe coil spring I6.

One of the releasing triggers shown in Fig. 5'

is disposed in the wing of the plane so that movement of the releasingtrigger in a forward or sideward direction will cause a pull on thereleasing wire 21 and the operation of the extinguishing mechanism. Thetrigger shown in Fig. 5 is pivoted at 30 in order that it may rock in adirection longitudinally of the plane. Therefore, when it is rocked bydirect contact, there is a pull on the releasing wire 21. The laterallyextending bottom portion 3| has a wire 32 conmeeting the releasetriggers attached thereto. An outwardly extending member 33 is disposedon the upper portion of the release trigger 26 at substantially rightangles to the laterally extending member 3| so that a pull on the wire21 will cause a bell-crank action to provide a pull ing force on thereleasing wire 21,

A rack 35 is cut on the side of the rod H which engages a valve gear 36,which in turn operates a valve 31 disposed in the fuel line 38 leadingfrom the fuel tank I to the carbureter of the motor (not shown). Uponupward movement of the rod I5, the rack'34 moves the valve gear 35 tobring the valve 36 in the fuel line 31 to a closed position. When thepiston I4 is again forced to the bottom of the container I3 the rod I5moves downwardly and the rack portion 34 thereon engages the valve gear35 to move the valve 36 in the fuel line 31 to an open position, therebyopening the feed line 36 leading to the carbureter of the motor (notshown).

In operation it will be apparent that no bullet or any other object ofreasonable size will cause a leakage of the tank I because of thecompressed rubber 4 or other elastic substance which is disposed in thewalls of the tank I. Upon the plane being wrecked the release triggers26 will be operated, thereby causing a pull on the release wire 21 torelease the latching portion 24 and-the latching member 2| from thelatching portion 23 on the arm 20. The arm 30 is then freed and thecontainer I3, thereby forcing the extinguishing fluid through the lineI6 leading into the top of the fuel tank I. The nozzle I9 or any othersuitable member is disposed inside the tank I to spread theextinguishing fluid over the entire surface of the fuel in the tank I.Upon this upward movement of the rod I5 the rack 34 formed thereonengages a valvegear 35 to move the valve 36 to a closed position in thefuel line 31 leading to the carbureter of the motor.

It will be evident that any form of release triggers or the like may beused, One form is shown more particularly in Figs. 3, 4 and 5, althoughany other form of mechanism might be used.

Fig. 8 is a diagrammatic view of a modified form of mechanism forapplying extinguishing fluid to the surface of the fuel in the tank, andfor cutting off the fuel line leading to the carbureter of the motor ofthe airplane. In this. modification a tank 40 is provided withextinguishing fluid under pressure with a feed line 4| leading to thetank 42. The feed line 43 leads to the carbureter of the motor of theairplane knot shown). Gear valves 44 and 45 are disposed in the fuellines 4| and 43 respectively.. A rack 46 common to both gear valves 44and 45 engage the gear valves 44 and 45 to move them to open and closedpositions. The rack 46 is= connected to mechanism such as the arm 20shown in Fig. 6. It will be apparent that many forms of latchingmechanisms and the like may be used to operate the rack'gear 46 manuallyand through releasing wires and the like.

It will be apparent that I have provided a fool-proof fuel tank for anairplane which is bullet proof and which brings the danger of fire to anairplane to an absolute minimum through the manipulation of one control.By releasing the master control which is the arm 20 as shown in Fig. 6,the pilot can close the fuel line 31, leading to the carbureter of themotor and at the same time open the valve of a pressure tank as shown inmy modified form of construction, which will extinguish or prevent anyfire, or the extinguishing system shown in Fig. 6 might be utilized withthe master control. A pressure spray inside the tank sprays the fluid inevery direction.

Various changes may be made in the specific embodiment of the presentinvention without departing from the spirit thereof or from the scope ofthe appended claims.

What I claim is:

1. A fuel tank for an airplane comprising a closed: vessel having aninner wall, rubber surrounding said inner wall, an outer wall coveringthe sides of said vessel, telescopically disposed outer end memberscovering the ends of said vessel, and means for drawing the outer endsof said vessel inwardly to compress the rubber between said inner andouter walls,

2. A fuel tank for an airplane comprising a closed vessel having innerand outer walls, corrugated rubber material between said inner and outerwalls, and means for compressing said the spring I8 forces the piston I4upwardly in material. 4

-3. A fuel tank for an airplane, comprising a closed vessel having innerand outer walls, wavy rubber sheet material disposed between said innerand-outer walls, and means for compressing said material.

GERRIT VAN DAAM.

